Possible Mechanism Of Referred Pain In Perineum And Pelvic Floor Associated With Prostate

Background: Persistent pain is not only the most prominent manifestation of chronic prostatitis but also the only symptom that significantly reduced the quality of life and functional status of these individuals. Since referred pain from visceral organs is considered a neurological event, it appeared reasonable to hypothesize that the persistent pain associated with prostate might also be explained by neural mechanisms. Objectives: To confirm the neural correspondence between the prostate and perineum, pelvic floor by electrophysiologic means and retrograde fluorescent double labeling.Methods. The retrograde fluorescent double labeling of sensory neurons and electrophysiological techniques were used. Electrophysiological techniques can be used as a functional marker for the response of referred areas under the stimulation of the prostate. The prostate was electrically stimulated, and the elicited action potentials of the nerves to pelvic floor and compound muscle action potentials of anal external sphincter were serially recorded. The fluorescent double labeling can provide a cellular method to confirm the peripheral process of DRG(dorsal root ganglion) cells dichotomizes to the prostate and external anal sphincter, somatic parties. Propidium Iodide(PI)was injected into the prostate, Bisbenzimide(Bb)into the external anal sphincter, genitofemoral, iliohypogastric, ilioinguinal, femoral, lateral femoral cutaneous nerve. The scara-lumbar DRGs were dissected and sectioned, analyzed with a Nikon fluorescence microscope. Then, Nickel ammonium sulfate-intensified immunocyto-chemistry of calcitonin gene-related peptide(CGRP) and P substance(SP) were carried out on those slides that have fluorescence double-labeling DRG cells. Thus, fluorescent double labeling can be used as an anatomical marker for a specific population of nociceptive cells within the DRG. Results:(1) Reflex action potentials were elicited in the genitofemoral(GF), ilioninguinal(II), iliohypogastric(IH) nerves by electrical stimulation of the prostate; the action potentials of GF were not influenced by transection of the cervical spinal cord, whereas they disappeared immediately after death, which indicates that they are induced by a spinal reflex; The action potentials were reduced considerably after destruction ofLumbar-sacral sympathetic trunks, suggesting that sympathetic nerve comprise an afferent path of the reflex;(2)compound muscle action potential (CMAP ) of anal external sphincter were induced by electrical stimulation of the prostate, suggesting that pelvic floor muscle will contract or spasm under the stimulation of the prostate;(3)The fluorescent double labeled cells were found in the L1-L2 and L6-S2 dorsal root ganglia (DRG), and some of them were confirmed to contain calcitonin gene-related peptide(CGRP) and P substance(SP), which the referred pains in pelvic floor may be caused by axon reflex in the peripheral process of DRG cells.Conclusions: (1)The prostate had spatial relation to the pelvic floor and perineum via spinal reflex. Electrical stimulation of the prostate induced reflex discharges in the nerves to the pelvic floor and perineum. It was postulated that the reflex discharges are related to muscle contraction resulting in referred pain in the pelvic floor and perineum;(2)The peripheral process of DRG cells dichotomizes to the prostate and the pelvic floor and perineum, and some of cells contain CGRP and SP, which indicate that the referred pains in pelvic floor and perineum induced by the prostate may be caused by " axon reflex" in the peripheral process of the DRG cells. Such relations suggest that a disorder in the prostate may be a possible source of pelvic floor and perineum referred pain; (3)Our results strongly suggest that referred pain status in inflammation of the prostate is neurogenically mediated; The persistent pain associated with prostate is correlated with pelvic floor muscle dysfunction; Electrical modulating nerve and muscle will be one of effective stratagems of treating pain of chronic...